Leads of multiple transistors are often soldered to a common substrate or printed circuit board in hybrid circuit assemblies. When transistors are further joined to a heat sink with screws, a difference in thermal expansion coefficients for the substrate or printed circuit board and the heat sink results in stress on solder joints as assemblies are thermally cycled. These stresses cause solder creep between the transistor leads and the substrates, eventually causing distortion of the leads and electrical failure.
There is a need for a more reliable multiple transistor clamping device that provides for mounting of multiple transistor assemblies to a heat sink while simultaneously minimizing thermal expansion forces due to differences in thermal expansion coefficients